Gilman, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.3 °C (low) to 12.1 °C (high). Annual precipitation averages 964.2 Millimeters. Gilman is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15.2 °C | -3.4 °C | 54.1 mm |
| February | -14.7 °C | -1.3 °C | 51.82 mm |
| March | -8.8 °C | 3.8 °C | 52.07 mm |
| April | -1.3 °C | 11.3 °C | 73.66 mm |
| May | 5.1 °C | 18.9 °C | 94.49 mm |
| June | 10.2 °C | 23.6 °C | 98.04 mm |
| July | 13 °C | 26.2 °C | 100.08 mm |
| August | 12 °C | 25.4 °C | 102.36 mm |
| September | 7.8 °C | 21.3 °C | 88.39 mm |
| October | 1.8 °C | 13.6 °C | 99.57 mm |
| November | -3.6 °C | 6.2 °C | 70.61 mm |
| December | -10 °C | -0.3 °C | 78.99 mm |
| Annual | -0.3 °C | 12.1 °C | 964.18 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |